The DSM also fails to distinguish between personality, personality traits, character, temperament, personality styles (Theodore Millon's contribution) and full-fledged personality disorders. It does not accommodate personality disorders induced by circumstances (reactive personality disorders, such as Milman's proposed "Acquired Situational Narcissism"). Nor does it efficaciously cope with personality disorders that are the result of medical conditions (such as brain injuries, metabolic conditions, or protracted poisoning). The DSM had to resort to classifying some personality disorders as NOS "not otherwise specified", a catchall, meaningless, unhelpful, and dangerously vague diagnostic "category".
One of the reasons for this dismal taxonomy is the dearth of research and rigorously documented clinical experience regarding both the disorders and various treatment modalities. Read this week's article to learn about the DSM's other great failing: many of the personality disorders are "culture-bound". They reflect social and contemporary biases, values, and prejudices rather than authentic and invariable psychological constructs and entities.
(From the book "Malignant Self-love: Narcissism Revisited" by Sam Vaknin - Click on this link to purchase: http://www.narcissistic-abuse.com/thebook.html)